(a) Field of the Invention
The present invention relates to a printed circuit board (PCB) and a display device using the same, and more particularly, to a PCB having excellent exfoliation resistance of embedded contact pad portions and a display device using the same.
(b) Description of Related Art
Recently, with rapid development of semiconductor technology, a demand for small-sized and low weight flat panel display devices having improved performance has explosively increased.
Among the flat panel display devices, a liquid crystal display (LCD) device has advantages of small size, low weight, and low power consumption. Therefore, much attention has been paid to the LCD device as an alternative to existing cathode ray tube (CRT) display devices. As a result, LCD devices are widely used for almost all information processing apparatuses requiring display devices.
In a typical LCD device, a specific molecular alignment of liquid crystal cells in a liquid crystal layer is changed into another molecular alignment by applying a voltage across the liquid crystal layer. Changes in magnitude of the voltage that is applied across the liquid crystal layer cause a change of optical characteristics of the liquid crystal cells, such as birefringence, optical rotary power, dichroism, optical scattering, etc., which are converted into a visual change. In other words, a typical LCD device is a light-receiving type of display device, which displays information using optical modulation of the liquid crystal cells.
In a conventional LCD device, a PCB is electrically driven so as to display images on an LCD panel containing the liquid crystal layer and electrically connected to the PCB. The PCB is electrically connected to a control board via a connector, and a driving signal and power are supplied to the PCB through the control board. Hereinafter, the PCB and the control board will be explained in detail with reference to FIG. 9.
FIG. 9 is a schematic diagram showing a connection of a conventional PCB 900, and schematically shows the conventional PCB 900 provided with a connector 130, which is connected to a socket 132 of a control board (not shown).
In a conventional process of manufacturing the conventional PCB 900 to be used in a display device, as shown by double arrow 1 in FIG. 9, a process of attaching the socket 132 with the connector 130 and a process of detaching the socket 132 from the connector 130 are repeated in order to inspect a quality of products. In such case, since the socket 132 is strongly fixed to the connector 130 while attaching the socket 132 to the connector 130, stress due to repetition of the attaching and detaching process causes stress on the connector 130 in an upward and downward direction, as shown by arrow 2.
As a result of the stress, a connector grounding part positioned on a connecting pad 800 of the PCB 900 such as, for example, a part for supporting the connector 130, is damaged. Therefore, the connecting pad 800 may become loose and be exfoliated from the PCB 900.
In response to exfoliation of the connecting pad 800 from the PCB 900, the PCB 900 must be replaced entirely. Thus, there is a problem in that quality of a process for manufacturing a display device decreases and cost of manufacture increase due to replacement of the PCB 900.